DESCRIPTION (From the Applicant?s Abstract): The long-term objectives of this proposal are to gain a better understanding of the mechanisms of angiogenesis through the study of periorbital hemangiomas, to design new treatments for theses tumors based on their biological characteristics, and to apply these findings to the study of ocular angiogenesis. Hemangiomas are vascular tumors that grow rapidly and then undergo spontaneous involution. Thus this tumor represents an excellent model to study proliferative and involutional phases of angiogenesis; insight gained into mechanism should be applicable to understanding and developing treatments for neovascular eye diseases in general, the leading causes of visual loss in Americans. These tumors frequently occur periorbitally and threaten vision, giving a second level of relevance to the eye. We will use multiphoton confocal microscopy to study integrin expression in human hemangioma specimens. An animal model of hemangioma has been established and will allow us to test new approaches to the treatment of these lesions. While in vitro investigations will determine, at the molecular level, the role of integrins in hemangioma. Proliferating hemangioma will be coompard to hemangioma in the involtuing phase in terms of gene expression using microassay technology to identifygenes involved in growth and regression. Insight into angiogenic mechanism gained from these studies should be applicable to other diseases with an angiogenic component such as diabetic retinopathy, macular degeneration, arthritis and cancer.